Comments on: Poduhvat’s Contra-Rotating Wind Turbines Could Produce 5 Times More Powerhttp://inhabitat.com/whetar-contra-rotating-turbine-is-compact-silent-and-designed-for-the-city/
Green design & eco innovation for a better worldTue, 03 Mar 2015 18:07:25 +0000hourly1http://wordpress.org/?v=3.9.1By: dr.a.jagadeeshhttp://inhabitat.com/whetar-contra-rotating-turbine-is-compact-silent-and-designed-for-the-city/comment-page-1/#comment-550794
Mon, 01 Jul 2013 05:47:41 +0000http://inhabitat.com/?p=519135#comment-550794Excellent. But the highest efficiency of a Wind turbine cannot cross 59.9%(Betz Limit).
Dr.A.Jagadeesh Nellore(AP),India
]]>By: justicegreenhttp://inhabitat.com/whetar-contra-rotating-turbine-is-compact-silent-and-designed-for-the-city/comment-page-1/#comment-534207
Sun, 16 Jun 2013 09:47:53 +0000http://inhabitat.com/?p=519135#comment-534207This is one of most innovative design I have seen. And I have seen them a lot.
What never seem to amaze how often you may find internet trolls acting as advocates of conventional wind industry when ever something new comes up.
This design is very much different than Flo design not just because of different aerodynamics but because of totally different system of contrarotating rotors they are using. These people are developing this technology for more than six years which is also available on their web sites. Therefore in that case every other company cited in previous comment can be clone of this one. But because it is not conceived in America than i guess it is impossible to be a trailblazer right?
The guy is talking about aerodynamics 101 without understanding the basic fact about design he is commenting or how it works. In this case diffuser is separated from duct and as such does not make rotor input . Its purpose is is to create the area of high pressure around the turbine which can clearly be seen from the pictures provided. The only thing which can be used in terms of calculating efficiency is rotor rotation comparing to velocity of wind inside the duct. With simple calculation it can be easily calculated that pressure area is much bigger than highest diameter of this turbine.
When it comes to avian friendly to the birds eyes and bats sonar this turbine looks as solid block of mass to them especially when it comes to sonar click. Therefore to them this turbine would look as if they are flying to the wall(or traffic sign) and I still haven’t seen any bird or bat colliding with them. Therefore this solution is much more avian friendly than any other conventional wind turbine solution.
I hope readers won’t mind my elaborated explanation but in terms of justice and support of this young company or any other future company which may be under attack of established (wind) industry trolls this must have been said.
]]>By: aerofox02http://inhabitat.com/whetar-contra-rotating-turbine-is-compact-silent-and-designed-for-the-city/comment-page-1/#comment-531678
Sat, 15 Jun 2013 00:16:30 +0000http://inhabitat.com/?p=519135#comment-531678Hmmm. Let\\\’s see here. Did a quick patent search on this design..and nothing..nope…nada. Although the Founder has some patent pending applications from years ago on other designs, I could not find any patents or pending applications on this design. For the most part, patents are meaningless, but nonetheless, if you make a claim to have them and they are not there..red flag? Pls send link if there is one. I could be wrong. So a few questions for this very dubious \\\”breakthrough\\\”. Kari Appa worked on contra-rotating turbines in the late 80\\\’s and 90\\\’s. The ducted wind turibne design is 150 years old..from France. check out Eolienne Bollee…the genesis.

1. Is this a FloDesign MEWT clone? Looks exactly like it. Also borrows from a contra-turbine design by Pivotal Aero, a R&D startup. What\\\’s different from ElenaEnergie, OptiWind, Arista Power or EnfloTec GmBH. BTW all these cos have patents, not pending applications and they are verifiable.

2. Aerodynamics 101. The reference area of a ducted turbine is the shroud, duct exit area, not the prop(s). That is a spurious reference. Autodesk is virtual, nature is unsteady. Checked the site, no real turbine appears to exist. Only virtual renderings. Any real world data from a prototype/model with actual photos/videos? Any MCS certification to backup your claims?

3. Bird friendly and works at lower wind speeds! Ha. There is no power in low wind speeds > 5 mph and again where\\\’s the data to backup claims on avian friendliness. Avians/bats have not adapted to MW size un-ducted turbines with high tip speeds. Do you expect anyone to believe that somehow avians/bats won\\\’t fly through a duct with claimed higher rpm from contra-rotation.
Is there an orinthologist on your design team?

4. 5x more power, doubtful, even if measured against the propeller area, certainly not when referenced against the duct exit area of the second stage.

not saying it isn\\\’t possible, just not attainable by this design, and the website has no meaningful research, studies or applicable reference patents to backup their claims.

]]>By: aerofox02http://inhabitat.com/whetar-contra-rotating-turbine-is-compact-silent-and-designed-for-the-city/comment-page-1/#comment-531632
Fri, 14 Jun 2013 23:17:23 +0000http://inhabitat.com/?p=519135#comment-531632Is this a FloDesign-MEWT clone?, and seems to be borrowing from the contra-turbine design that is still in R&D by Pivotal Aero, both are US cos., with patents. What’s different about this one than say the other two R&D cos and Arista Power or Elena Energie or EnfloTec-GMBH, OptiWind even.

I believe all the cos that are developing turbines such as these have multiple patents. Which quite frankly are useless, but nevertheless.. Also the correct reference area is the Exit Diameter of the shroud or duct- AeroDynamics 101. What is the comparison in terms of efficiency to an un-ducted turbine of comparable swept area, as the exit area of the shroud. 1st Clue-it isn’t 5x more energy-not even close.

How do you know it is avian friendly? Any real world tests or certification to back up your claims? Autodesk is virtual….nature is un-steady! What’s to stop a bird from flying through the duct, if these claimed super-efficient blades have higher rpm than an un-ducted wind turbine. Birds have yet to adapt to MW size rotor blades with high tip speeds. How do you expect avians/bats to see or echo-locate the blades in a duct that are operating between 800-1200 rpm.?

I checked the site and nothing but digital graphics. Didn’t see a photo of a real turbine anywhere, not even a prototype or test model. Highly skeptical of the 5x energy capture claim.

you can not get them in Australia anywhere but shipment from Europe is possible. You can send your request onoffice@poduhvat-hydrokinetics.co.uk for all informations concerning Whetar 10 wind turbine.

]]>By: Justin Casehttp://inhabitat.com/whetar-contra-rotating-turbine-is-compact-silent-and-designed-for-the-city/comment-page-1/#comment-528618
Wed, 12 Jun 2013 07:21:50 +0000http://inhabitat.com/?p=519135#comment-528618How much are they where can i get them in Australia. and do you have a video on You-tube showing wind speed and amps at the same time. What is there start up speed.
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